A treatment method for organic wastewater containing alcohols and ethers

Abstract

To overcome the problem of low COD removal rate in the treatment of wastewater generated in the existing ethylene glycol production process using the traditional Fenton oxidation method, the present application provides a method for treating alcohol- and ether-containing organic wastewater, comprising the following steps: adjusting the pH value of the wastewater to 2.5-4.5; adding an oxidant and a catalyst to the wastewater after adjusting the pH value, and carrying out an oxidation reaction under an aeration state; wherein, the catalyst is blown into the wastewater through a microporous aerator; adjusting the pH value of the wastewater after the oxidation reaction to 7.5-11, filtering and then carrying out biochemical treatment to obtain the water body to be discharged; the particle size d of the catalyst and the flow rate m of the aeration gas satisfy the following conditions: d / 300 ≤ m ≤ d / 200, and 150 ≤ d ≤ 500, 1 ≤ m ≤ 2, d is the particle size of the catalyst, unit nm; m is the flow rate of the aeration gas, unit m 3 / h. In the treatment method provided by the present application, the aeration gas of the microporous aerator can evenly blow the nanoscale catalyst into the wastewater, with better catalytic effect, and the COD removal rate in the wastewater can reach >97%.

Description

Technical Field

[0001] The present invention belongs to the technical field of wastewater, and particularly relates to a method for treating organic wastewater containing alcohols and ethers. Background Art

[0002] Industrial wastewater is the main source of water environmental pollution in China. With the continuous expansion of production scale and the rapid development of industrial technology, the pollution sources of wastewater with high COD are increasing day by day. High-COD wastewater is mostly treated by traditional chemical oxidation methods. The chemical oxidation method is to convert refractory organic matter into easily degradable organic matter through the oxidation of oxidants, or to completely oxidize organic matter into H2O, CO / CO2. At present, the main chemical oxidation methods for the advanced treatment of industrial wastewater include chlorine oxidation, Fenton oxidation, ozone oxidation, and electrochemical oxidation. Among them, the Fenton oxidation method mainly has the following problems in the wastewater treatment process: (1) a large amount of iron salts are used, generating a large amount of flocculent precipitation; (2) there are many substances that cannot be degraded, and there are certain limitations in application; (3) the degradation efficiency is low. When the wastewater COD exceeds 10,000, the degradation efficiency is often lower than 50%. Industrial wastewater can only be treated by biodegradation methods for wastewater with a COD less than 5,000. When the wastewater COD is too high, water needs to be added for dilution, which not only causes waste of water resources, but also increases the treatment cost due to excessive water output.

[0003] During the production process of ethylene glycol, a large amount of wastewater containing about 5% ethylene glycol monomethyl ether and trace amounts of ethylene glycol and methanol is generated, with a COD≈120,000 - 150,000. If directly discharged into the biochemical pool, it will cause a large number of bacteria to die. In addition, since ethylene glycol monomethyl ether and water form an azeotrope and cannot be separated by distillation, the recovery is difficult; when using the traditional Fenton oxidation method to treat the wastewater, the COD removal rate is only about 50%, far from meeting the current treatment requirements for this kind of wastewater. Therefore, there is an urgent need to develop a method that can efficiently treat this kind of ultra-high COD wastewater. Summary of the Invention

[0004] In view of the technical problem of low COD removal rate when treating the wastewater generated during the above ethylene glycol production process using the traditional Fenton oxidation method, the present application provides a method for treating organic wastewater containing alcohols and ethers.

[0005] The technical solutions adopted by the present invention to solve the above technical problems are as follows:

[0006] On the one hand, the present application provides a method for treating organic wastewater containing alcohols and ethers, including the following steps:

[0007] Adjust the pH value of the wastewater to 2.5 - 4.5;

[0008] An oxidant and a catalyst are added to the wastewater after adjusting the pH value, and an oxidation reaction is carried out under aeration; wherein the catalyst is blown into the wastewater through a microporous aerator;

[0009] The pH value of the wastewater after the oxidation reaction is adjusted to 7.5-11, filtered and then biochemically treated to obtain the water body to be discharged;

[0010] The particle size d of the catalyst and the flow rate m of the aeration gas meet the following conditions:

[0011] d / 300≤m≤d / 200, and 150≤d≤500, 1≤m≤2;

[0012] Wherein, d is the catalyst particle size, in nm;

[0013] m is the gas flow rate during aeration, unit is m 3 / h.

[0014] Preferably, the particle size d of the catalyst and the flow rate m of the aeration gas satisfy the following condition: d / 250≤m≤d / 220.

[0015] Preferably, the particle size d of the catalyst is 200≤d≤300; and the range of m is 1.2 to 1.5.

[0016] Preferably, the catalyst is nano-sized ferrous sulfate.

[0017] Preferably, when the pH value of the wastewater is adjusted to 2.5-4.5, an acid regulator is used to adjust the pH value of the wastewater, and the acid regulator includes one or more of sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid.

[0018] Preferably, the oxidant is hydrogen peroxide with a mass concentration of 30%-80%;

[0019] Based on the mass of the wastewater being 100%, the mass content of the catalyst is 0.1% to 0.5%, and the mass content of the oxidant is 1% to 10%.

[0020] Preferably, the microporous aerator is a tubular microporous aerator.

[0021] Preferably, the oxidation reaction is carried out under light conditions, wherein the light conditions are ultraviolet light irradiation, and the wavelength range of the ultraviolet light is 200 to 380 nm;

[0022] The ultraviolet light is emitted by an ultraviolet lamp, and the power range of the ultraviolet lamp is 20 to 60W;

[0023] The power required for the wastewater is 500-1000W / m 3 .

[0024] Preferably, the ultraviolet light irradiation time is 1 h to 2 h, and the oxidation reaction time is 1 h to 2 h.

[0025] Preferably, when adjusting the pH value of the wastewater to 7.5 - 11, an alkaline regulator is used to adjust the pH value of the wastewater, and the alkaline regulator includes one or more of calcium oxide, sodium hydroxide, and potassium hydroxide.

[0026] Beneficial effects:

[0027] (1) The particle size d of the catalyst and the gas flow rate m of the aeration satisfy the condition d / 300 ≤ m ≤ d / 200, and 150 ≤ d ≤ 500, 1 ≤ m ≤ 2. The aeration gas of the microporous aerator can evenly disperse the catalyst in the wastewater. The catalyst has a wider contact area in the wastewater, better catalytic effect, which is beneficial to improving the oxidation reaction efficiency, and has excellent treatment effect on organic wastewater containing linear alcohols such as ethylene glycol monomethyl ether, ethylene glycol, methanol, and ethanol, and has the effect that the COD removal rate in the wastewater > 97%.

[0028] (2) The treatment method of alcohol- and ether-containing organic wastewater provided by this application can not only effectively treat the ultra-high COD wastewater of ethylene glycol monomethyl ether in a safe, environmentally friendly, fast, and efficient manner, but also greatly reduce the treatment cost of the wastewater. [[ID=!4]]Specific embodiments

[0029] In order to make the technical problems, technical solutions, and beneficial effects solved by the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0030] On the one hand, this application provides a treatment method for alcohol- and ether-containing organic wastewater, including the following steps:

[0031] Adjust the pH value of the wastewater to 2.5 - 4.5;

[0032] Add an oxidant and a catalyst to the wastewater after adjusting the pH value, and carry out an oxidation reaction under an aeration state; wherein, the catalyst is blown into the wastewater through a microporous aerator;

[0033] Adjust the pH value of the wastewater after the oxidation reaction to 7.5 - 11, filter it, and then carry out biochemical treatment to obtain the water body to be discharged;

[0034] The particle size d of the catalyst and the flow rate m of the aeration gas satisfy the following conditions:

[0035] d / 300 ≤ m ≤ d / 200, and 150 ≤ d ≤ 500, 1 ≤ m ≤ 2;

[0036] Wherein, d is the particle size of the catalyst, and the unit is nm;

[0037] m is the gas flow rate during the aeration, with the unit of m 3 / h.

[0038] During the existing ethylene glycol preparation process, a large amount of wastewater containing ethylene glycol monomethyl ether and trace amounts of ethylene glycol, methanol, ethanol, etc. is generated. When using the traditional chemical oxidation method to treat the wastewater, the COD removal rate is low. Through a large amount of research, the inventor found that during the process of chemically oxidizing the wastewater, adding a catalyst and dispersing the catalyst in the wastewater through the aeration gas of a microporous aerator. The catalyst has a large specific surface area, is evenly distributed in the wastewater, has a wider contact area, better catalytic effect, higher oxidation reaction rate, and higher COD removal rate.

[0039] Compared with the prior art, the method for treating alcohol- and ether-containing organic wastewater provided by the present application has the following effects: (1) The particle size d of the catalyst and the gas flow rate m of the aeration satisfy the condition d / 300 ≤ m ≤ d / 200, and 150 ≤ d ≤ 500, 1 ≤ m ≤ 2. The aeration gas of the microporous aerator can evenly disperse the catalyst in the wastewater. The catalyst has a wider contact area in the wastewater, better catalytic effect, which is beneficial to improving the oxidation reaction efficiency, and has excellent treatment effect on organic wastewater containing linear alcohols such as ethylene glycol monomethyl ether, ethylene glycol, methanol, and ethanol, with the COD removal rate in the wastewater > 97%. (2) The method for treating alcohol- and ether-containing organic wastewater provided by the present application can not only effectively treat the ultra-high COD wastewater of ethylene glycol monomethyl ether in a safe, environmentally friendly, fast and efficient manner, but also greatly reduce the treatment cost of the wastewater.

[0040] The present application provides a method for treating alcohol- and ether-containing organic wastewater, which is mainly used for treating ultra-high COD wastewater generated during the ethylene glycol production process, that is, for the backend of a continuous ethylene glycol production device to continuously treat wastewater with ultra-high COD (COD in the wastewater = 120,000 - 150,000) containing 1% - 3% ethylene glycol monomethyl ether, 0.5% - 1% ethylene glycol, 0.1% - 0.5% methanol, 0.1% - 0.5% dimethyl carbonate and other organic substances generated in the ethylene glycol dehydration process.

[0041] Specifically, when the particle size d of the catalyst and the gas flow rate m of aeration satisfy the condition d / 300 ≤ m ≤ d / 200, and 150 ≤ d ≤ 500, 1 ≤ m ≤ 2, the aeration gas of the microporous aerator can evenly disperse the catalyst in the wastewater, and the catalyst is evenly distributed in the wastewater with good effect, which is beneficial to catalyze the oxidation reaction in the wastewater, improve the reaction rate, and increase the removal rate of COD in the wastewater. When m < d / 300, the aeration gas flow rate is slow, and the gas flow rate is small relative to the catalyst with a certain particle size, so that the catalyst powder cannot be evenly blown into the wastewater, resulting in uneven distribution of the catalyst powder in the wastewater. Most of the catalyst powder is distributed in the back-end wastewater, and the catalytic oxidation reaction rate of the wastewater at the front end of the aeration tank is low, and the overall wastewater treatment effect is poor. Moreover, the microporous aerator is prone to blockage, reducing the oxidation reaction in the wastewater and affecting the wastewater treatment efficiency. When m > d / 200, the aeration gas flow rate is large relative to the catalyst with a certain particle size, and the aeration gas blows the catalyst powder too fast, resulting in most of the catalyst powder being distributed in the front-end wastewater of the aeration tank, and the catalytic oxidation reaction rate of the wastewater at the back end of the aeration tank is low, and the wastewater treatment effect is poor.

[0042] In some preferred embodiments, the particle size d of the catalyst and the flow rate m of the aeration gas satisfy the following conditions: d / 250 ≤ m ≤ d / 220, which is more conducive to evenly blowing the catalyst into the wastewater by the aeration gas, and the catalyst is more evenly distributed in the wastewater, catalyzing the oxidation reaction in the wastewater, improving the reaction rate, and having a higher removal rate of COD.

[0043] In some embodiments, the particle size d range of the catalyst is 150 ≤ d ≤ 500. When the particle size d of the catalyst is less than 150, the particle size of the catalyst is small, and the specific surface area of the catalyst particles is large, so it is easy to agglomerate, which is not conducive to evenly blowing it into the wastewater. If the particle size of the catalyst is greater than 500, the particle size of the catalyst is large, and the catalyst particles are large, and a larger aeration gas flow rate is required to blow the catalyst into the wastewater, increasing the wastewater treatment cost. At the same time, the contact area between the catalyst and the wastewater becomes smaller, which is not conducive to the catalytic reaction. Specifically, the particle size d of the catalyst can be 150, 200, 230, 250, 207, 209, 300, 310, 330, 350, 360, 380, 400, 420, 450, 460, 480 or 500.

[0044] In some preferred embodiments, the particle size d of the catalyst is 200 ≤ d ≤ 300. The nano-scale catalyst within this preferred range is more conducive to evenly blowing the catalyst into the wastewater by the aeration gas and improving the catalytic reaction rate.

[0045] In some embodiments, based on the mass of the wastewater being 100%, the mass content of the catalyst is 0.1% to 0.5%. Compared with the prior art, the catalyst provided in this application can evenly distribute the catalyst in the wastewater through the aeration gas of the microporous aerator. Adding 0.1 wt% to 0.5 wt% of the catalyst can achieve a good catalytic reaction effect, improve the oxidation reaction rate, and increase the removal rate of COD. Specifically, the addition amount of the catalyst can be 0.1%, 0.13%, 0.15%, 0.18%, 0.2%, 0.25%, 0.28%, 0.3%, 0.32%, 0.35%, 0.4%, 0.45%, 0.47%, or 0.5%. If the mass content of the catalyst is less than 0.1%, the catalyst cannot be evenly distributed in the wastewater, reducing the catalytic efficiency. If the mass content of the catalyst is higher than 0.5%, the addition amount of the catalyst increases, increasing the cost of wastewater treatment.

[0046] In some embodiments, the catalyst is nanoscale ferrous sulfate.

[0047] In some embodiments, the gas flow rate m of the microporous aerator ranges from 1 m 3 / h to 2 m 3 / h. Specifically, m can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0. Preferably, the range of m is 1.2 to 1.5. When the gas flow rate of the microporous aerator is within 1 m 3 / h to 2 m 3 / h, it can evenly blow the catalyst with a particle size of 150 nm to 500 nm into the wastewater and can reduce the cost of wastewater treatment. When the particle size d of the catalyst is within 200 to 300 nm and the gas flow rate m is within 1.2 to 1.5 m 3 / h, meeting m and d within the above ranges, the microporous aerator can evenly blow the catalyst into the wastewater, making the catalyst evenly distributed in the wastewater and at the same time reducing the cost of wastewater treatment.

[0048] In some embodiments, when adjusting the pH value of the wastewater to 2.5 to 4.5, an acid regulator is used to adjust the pH value of the wastewater, and the acid regulator includes one or more of sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid.

[0049] In some preferred embodiments, sulfuric acid is used to adjust the pH value of the wastewater.

[0050] In some embodiments, the oxidant is hydrogen peroxide with a mass concentration of 30% to 80%. Based on the mass of the wastewater being 100%, the mass content of the oxidant is 1% to 10%. Using hydrogen peroxide with a mass concentration of 30% to 80%, the hydrogen peroxide concentration is high, and the added hydrogen peroxide helps to promote the oxidation reaction rate in the wastewater. If the mass content of hydrogen peroxide is less than 1%, the content of hydrogen peroxide added in wastewater treatment is low, and it is impossible to effectively improve the wastewater treatment efficiency. If the mass content of hydrogen peroxide is higher than 10%, although it can oxidize the organic matter in the wastewater, the usage amount of hydrogen peroxide increases, and the hydrogen peroxide exceeding this content range cannot further improve the wastewater treatment efficiency, but also increases the treatment cost. Specifically, the mass content of the oxidant can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc., as long as the mass content of the oxidant is within the range of 1% to 10%. Preferably, the oxidant is hydrogen peroxide with a mass concentration of 50%.

[0051] In some embodiments, the microporous aerator is a tubular microporous aerator.

[0052] Specifically, using a microporous aerator can not only evenly distribute the nanoscale catalyst into the wastewater to be treated, but also timely discharge the carbon dioxide and low-molecular-weight products generated during the decomposition and mineralization of organic matter from the wastewater to be treated, promoting the reaction to move in the positive direction and improving the COD removal rate.

[0053] In some embodiments, the oxidation reaction is carried out under light conditions, the light conditions are ultraviolet light irradiation, and the wavelength range of the ultraviolet light is 200 to 380 nm; the ultraviolet light is emitted by an ultraviolet lamp, and the power range of the ultraviolet lamp is 20 to 60 W; the power required for the wastewater is 500 to 1000 W / m 3 。

[0054] Specifically, the power required for the wastewater is 500 to 1000 W / m 3 That is, the power required for each cubic meter of wastewater treatment is 500 to 1000 W, and the number of ultraviolet lamps can be selected according to this requirement. The ultraviolet lamp provides energy for the oxidation reaction in the wastewater and promotes the progress of the reaction.

[0055] In some embodiments, the ultraviolet light irradiation time is 1 h to 2 h, and the oxidation reaction time is 1 h to 2 h. It should be noted that the ultraviolet light irradiation time is the same as the oxidation reaction time.

[0056] In some embodiments, when adjusting the pH value of the wastewater to 7.5 to 11, an alkaline regulator is used to adjust the pH value of the wastewater, and the alkaline regulator includes one or more of calcium oxide, sodium hydroxide, and potassium hydroxide.

[0057] After adjusting the pH value of the wastewater using an alkali regulator, filter it, and subject the filtrate to biochemical treatment, such as using microorganisms to degrade the organic matter in the wastewater, so that the wastewater meets the discharge standards.

[0058] The present invention will be further described below through examples.

[0059] Example 1

[0060] This example is used to illustrate a method for treating alcohol- and ether-containing organic wastewater provided by the present application, including the following steps:

[0061] (1) Set the wastewater inlet rate of the wastewater comprehensive regulation tank to 800 kg / h, use dilute sulfuric acid with a concentration of 20% as the acid regulator, and the feeding rate of the dilute sulfuric acid is 0.5 kg / h. Adjust the pH value of the wastewater in the comprehensive regulation tank to 4.0.

[0062] (2) Add a hydrogen peroxide solution with a mass concentration of 50% to the wastewater obtained in step (1), and the feeding rate of the hydrogen peroxide solution is 64 kg / h.

[0063] (3) Transfer the above wastewater to a microporous aeration tank. Set 15 groups of ultraviolet lamps with a power of 60 W in the microporous aeration tank. The number of ultraviolet lamps in each group is 1, and the ultraviolet light emitted by each ultraviolet lamp is 254 nm. Set the aeration gas flow rate of the microporous aerator to 1 m 3 / h, and blow nano-ferrous sulfate into the wastewater through the aeration gas of the microporous aerator, where the feeding rate of nano-ferrous sulfate is 1.8 kg / h, the particle size d is 250 nm, and carry out an oxidation reaction for 2 h under the irradiation of ultraviolet light with a wavelength of 254 nm.

[0064] (4) After the above oxidation reaction is completed, pump the reaction liquid into a flocculation sedimentation tank. Use calcium oxide emulsion with a mass concentration of 5% as the alkali regulator, adjust the feeding rate of calcium oxide (5%) emulsion to 2 kg / h to adjust the pH value of the reaction liquid to 9.0, and then filter it through a filter press to remove iron ions. Take a sample to test the COD value of the filtrate, and the test results are shown in Table 1.

[0065] (5) Discharge the filtered clear liquid directly into the biochemical tank, and measure the COD value of the effluent after treatment in the biochemical tank. The test results are shown in Table 1.

[0066] Example 2

[0067] (1) Set the wastewater inlet rate of the wastewater comprehensive regulation tank to 800 kg / h, use dilute sulfuric acid with a concentration of 20% as the acid regulator, and the feeding rate of the dilute sulfuric acid is 0.8 kg / h. Adjust the pH value of the wastewater in the comprehensive regulation tank to 3.0.

[0068] (2) Add a hydrogen peroxide solution with a mass concentration of 80% to the wastewater obtained in step (1) at a feeding rate of 15 kg / h.

[0069] (3) Transfer the above wastewater to a microporous aeration tank. Set 15 groups of ultraviolet lamps with a power of 60 W in the microporous aeration tank. The number of ultraviolet lamps in each group is 1, and the ultraviolet light emitted by each ultraviolet lamp is 254 nm. Set the aeration gas flow rate of the microporous aerator to 1.4 m 3 / h. Blow nano-ferrous sulfate into the wastewater through the aeration gas of the microporous aerator, where the feeding rate of nano-ferrous sulfate is 3.5 kg / h, the particle size d is 300 nm, and carry out an oxidation reaction for 2 h under the irradiation of ultraviolet light with a wavelength of 254 nm.

[0070] (4) After the above oxidation reaction is completed, pump the reaction liquid into a flocculation sedimentation tank. The alkaline regulator uses a calcium oxide emulsion with a mass concentration of 5%. Adjust the feeding rate of the calcium oxide (5%) emulsion to 3 kg / h to adjust the pH value of the reaction liquid to 9.5, and then filter through a filter press to remove iron ions. Take a sample to test the COD value of the filtrate, and the test results are shown in Table 1.

[0071] (5) Discharge the filtered clear liquid directly into the biochemical tank, and measure the COD value of the effluent after treatment in the biochemical tank. The test results are shown in Table 1.

[0072] Example 3

[0073] (1) Set the wastewater inlet rate of the wastewater comprehensive regulation tank to 800 kg / h. The acid regulator uses dilute sulfuric acid with a concentration of 20%, and the feeding rate of the dilute sulfuric acid is 0.8 kg / h. Adjust the pH value of the wastewater in the comprehensive regulation tank to 3.0.

[0074] (2) Add a hydrogen peroxide solution with a mass concentration of 50% to the wastewater obtained in step (1) at a feeding rate of 70 kg / h.

[0075] (3) Transfer the above wastewater to a microporous aeration tank. Set 15 groups of ultraviolet lamps with a power of 60 W in the microporous aeration tank. The number of ultraviolet lamps in each group is 1, and the ultraviolet light emitted by each ultraviolet lamp is 254 nm. Set the aeration gas flow rate of the microporous aerator to 1.5 m 3 / h. Blow nano-ferrous sulfate into the wastewater through the aeration gas of the microporous aerator, where the feeding rate of nano-ferrous sulfate is 1 kg / h, the particle size d is 300 nm, and carry out an oxidation reaction for 2 h under the irradiation of ultraviolet light with a wavelength of 254 nm.

[0076] (4) After the above oxidation reaction is completed, the reaction solution is pumped into a flocculation sedimentation tank. The alkaline regulator is a calcium oxide emulsion with a mass concentration of 5%. The feeding rate of the calcium oxide (5%) emulsion is adjusted to 3 kg / h to adjust the pH value of the reaction solution to 9.5, and then it is filtered through a filter press to remove iron ions. A sample is taken to test the COD value of the filtrate, and the test results are shown in Table 1.

[0077] (5) The filtered clear liquid is directly discharged into the biochemical tank, and the COD value of the effluent is measured after being treated in the biochemical tank. The test results are shown in Table 1.

[0078] Example 4

[0079] The difference between Example 4 and Example 3 is that the feeding rate of nano-ferrous sulfate is 1 kg / h, the particle size d is 450 nm, and the aeration gas flow rate of the microporous aerator is set to 2.0 m 3 / h, and the rest is the same as in Example 3.

[0080] Example 5

[0081] The difference between Example 5 and Example 1 is that the particle size d of nano-ferrous sulfate is 200 nm, and the aeration gas flow rate of the microporous aerator is set to 1.0 m 3 / h, and the rest is the same as in Example 1.

[0082] Example 6

[0083] The difference between Example 6 and Example 1 is that the particle size d of nano-ferrous sulfate is 280 nm, and the aeration gas flow rate of the microporous aerator is set to 1.2 m 3 / h, and the rest is the same as in Example 1.

[0084] Example 7

[0085] The difference between Example 7 and Example 1 is that the particle size d of nano-ferrous sulfate is 350 nm, and the aeration gas flow rate of the microporous aerator is set to 1.5 m 3 / h, and the rest is the same as in Example 1.

[0086] Comparative Example 1

[0087] The difference between Comparative Example 1 and Example 1 is that in step (3), the particle size of ferrous sulfate is 450 nm, and the aeration gas flow rate of the microporous aerator is set to 1.0 m 3 / h. The rest is the same as in Example 1.

[0088] Comparative Example 2

[0089] The difference between Comparative Example 2 and Example 1 is that in step (3), the particle size of ferrous sulfate is 250 nm, and the aeration gas flow rate of the microporous aerator is set to 1.5 m 3 / h. The rest is the same as in Example 1.

[0090] Comparative Example 3

[0091] The difference between Comparative Example 3 and Example 1 lies in that step (3) is different. The specific content of step (3) is as follows:

[0092] Transfer the above wastewater to the aeration tank. Set 15 groups of ultraviolet lamps with a power of 60 W in the aeration tank. The number of ultraviolet lamps in each group is 1, and the ultraviolet light emitted by each ultraviolet lamp is 254 nm. Directly add nano-ferrous sulfate powder into the aeration tank, where the feeding rate of nano-ferrous sulfate is 1.8 kg / h, the particle size d is 250 nm, and carry out an oxidation reaction for 2 h under the irradiation of ultraviolet light with a wavelength of 254 nm. Among them, there are at least two ways to directly add nano-ferrous sulfate powder into the aeration tank: one is to sprinkle the nano-ferrous sulfate powder into the aeration tank; the other is to dissolve the nano-ferrous sulfate powder in water and then pour it into the aeration tank; either way can be selected.

[0093] The rest is the same as the steps in Example 1.

[0094] Comparative Example 4

[0095] The difference between Comparative Example 4 and Example 1 lies in that in step (3), the particle size of ferrous sulfate is 150 nm, and the aeration gas flow rate of the microporous aerator is set to 0.5 m 3 / h. The rest is the same as in Example 1.

[0096] Comparative Example 5

[0097] The difference between Comparative Example 5 and Example 1 lies in that in step (3), the particle size of ferrous sulfate is 550 nm, and the aeration gas flow rate of the microporous aerator is set to 2 m 3 / h. The rest is the same as in Example 1.

[0098] Table 1 COD values of wastewater before and after treatment in examples and comparative examples

[0099]

[0100] As can be seen from Table 1, when comparing Example 1 with Comparative Example 3, in Comparative Example 3, the catalyst was directly added to the wastewater without being blown into the wastewater through a microporous aerator. After the wastewater was treated by the method of Comparative Example 3, the COD removal rate was 27.83%, which was much lower than 97.41% in Example 1. The wastewater did not meet the requirements for direct biochemical treatment, indicating that blowing the catalyst into the wastewater through aeration can increase the catalytic oxidation rate of the wastewater and improve the COD removal rate of the wastewater. When comparing Example 1 with Comparative Examples 1-2, the values of d and m in Comparative Example 1 satisfied 150 ≤ d ≤ 500 and 1 ≤ m ≤ 2, but did not satisfy the relationship d / 300 ≤ m ≤ d / 200, and the COD removal rate after the wastewater oxidation treatment was relatively low, about 91% - 92%. When comparing Example 1 with Comparative Examples 4-5, the values of d and m satisfied the relationship d / 300 ≤ m ≤ d / 200, but the values of d or m did not satisfy the conditions of 150 ≤ d ≤ 500 and 1 ≤ m ≤ 2, and the COD removal rate of the wastewater was lower than 90%. It shows that the values of d and m should not only satisfy 150 ≤ d ≤ 500 and 1 ≤ m ≤ 2, but also satisfy the relationship d / 300 ≤ m ≤ d / 200, so that the aeration gas can evenly disperse the catalyst in the wastewater, the catalyst has a wider contact area in the wastewater, the catalytic effect is better, which is beneficial to improving the oxidation reaction efficiency, and has an excellent treatment effect on organic wastewater containing linear alcohols such as ethylene glycol monomethyl ether, ethylene glycol, methanol, and ethanol, and only then can the COD removal rate in the wastewater be > 97%.

[0101] When comparing Examples 1-7, the catalyst particle size d was in the range of 200 ≤ d ≤ 300, m was between 1.2 and 1.5, and d and m satisfied the relationship d / 250 ≤ m ≤ d / 220. The COD removal rate after the wastewater oxidation treatment reached 99.07%. It shows that meeting the above conditions is beneficial for the aeration to evenly blow the nano-catalyst into the wastewater and make it more evenly distributed in the wastewater, improving the catalytic oxidation efficiency of the wastewater, having an excellent treatment effect on organic wastewater containing alcohols and ethers, and having a higher COD removal rate.

[0102] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A treatment method for organic wastewater containing alcohols and ethers, characterized in that, It includes the following steps: Adjust the pH value of the wastewater to 2.5 - 4.5; Add an oxidant and a catalyst to the wastewater after adjusting the pH value, and conduct an oxidation reaction under an aeration state; wherein, the catalyst is blown into the wastewater through a microporous aerator; Adjust the pH value of the wastewater after the oxidation reaction to 7.5 - 11, filter it and then conduct biochemical treatment to obtain the water body to be discharged; the catalyst is nano-scale ferrous sulfate; The particle size d of the catalyst and the gas flow rate m of the aeration satisfy the following conditions: d / 300 ≤ m ≤ d / 200, and 150 ≤ d ≤ 500, 1 ≤ m ≤ 2; Wherein, d is the particle size of the catalyst, and the unit is nm; m is the gas flow rate during aeration, with the unit of m 3 / h.

2. The treatment method of the alcohol- and ether-containing organic wastewater according to claim 1, wherein The particle size d of the catalyst and the gas flow rate m of the aeration satisfy the following conditions: d / 250 ≤ m ≤ d / 220.

3. The treatment method of the alcohol- and ether-containing organic wastewater according to claim 1, characterized in that, The particle size d of the catalyst is 200 ≤ d ≤ 300; the range of m is 1.2 ≤ m ≤ 1.

5.

4. The treatment method of the organic wastewater containing alcohols and ethers according to claim 1, wherein When adjusting the pH value of the wastewater to 2.5 - 4.5, an acid regulator is used to adjust the pH value of the wastewater, and the acid regulator includes one or more of sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid.

5. The treatment method of the alcohol- and ether-containing organic wastewater according to claim 1, characterized in that, The oxidant is hydrogen peroxide with a mass concentration of 30% - 80%; Based on the mass of the wastewater being 100%, the mass content of the catalyst is 0.1% - 0.5%, and the mass content of the oxidant is 1% - 10%.

6. The treatment method of the alcohol- and ether-containing organic wastewater according to claim 1, wherein The microporous aerator is a tubular microporous aerator.

7. The method for treating organic wastewater containing alcohols and ethers according to claim 1, characterized in that, The oxidation reaction is carried out under light conditions, and the light conditions are ultraviolet light irradiation, and the wavelength range of the ultraviolet light is 200 - 380 nm; The ultraviolet light is emitted by an ultraviolet lamp, and the power range of the ultraviolet lamp is 20 - 60 W; The power required for the wastewater is 500 - 1000 W / m 3 .

8. The treatment method of the alcohol- and ether-containing organic wastewater according to claim 7, characterized in that, The irradiation time of the ultraviolet light is 1 h - 2 h, and the oxidation reaction time is 1 h - 2 h.

9. The treatment method of the alcohol- and ether-containing organic wastewater according to claim 1, wherein When adjusting the pH value of the wastewater to 7.5 - 11, an alkali regulator is used to adjust the pH value of the wastewater, and the alkali regulator includes one or more of calcium oxide, sodium hydroxide, and potassium hydroxide.

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